1/*
2 * Copyright (c) 1985, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
32 *
33 * Permission to use, copy, modify, and distribute this software for any
34 * purpose with or without fee is hereby granted, provided that the above
35 * copyright notice and this permission notice appear in all copies, and that
36 * the name of Digital Equipment Corporation not be used in advertising or
37 * publicity pertaining to distribution of the document or software without
38 * specific, written prior permission.
39 *
40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
47 * SOFTWARE.
48 */
49
50/*
51 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
52 *
53 * Permission to use, copy, modify, and distribute this software for any
54 * purpose with or without fee is hereby granted, provided that the above
55 * copyright notice and this permission notice appear in all copies.
56 *
57 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
58 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
59 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
60 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
61 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
62 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
63 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
64 * SOFTWARE.
65 */
66
67#include <sys/types.h>
68#include <sys/param.h>
69#include <netinet/in.h>
70#include <arpa/nameser.h>
71#include <ctype.h>
72#include <resolv.h>
73#include <stdio.h>
74#include <string.h>
75#include <unistd.h>
76
77/*
78 * Expand compressed domain name 'comp_dn' to full domain name.
79 * 'msg' is a pointer to the beginning of the message,
80 * 'eomorig' points to the first location after the message,
81 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
82 * Return size of compressed name or -1 if there was an error.
83 */
84int
85dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
86 char *dst, int dstsiz)
87{
88 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
89
90 if (n > 0 && dst[0] == '.')
91 dst[0] = '\0';
92 return (n);
93}
94libresolv_hidden_def (dn_expand)
95
96/*
97 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
98 * Return the size of the compressed name or -1.
99 * 'length' is the size of the array pointed to by 'comp_dn'.
100 */
101int
102dn_comp(const char *src, u_char *dst, int dstsiz,
103 u_char **dnptrs, u_char **lastdnptr)
104{
105 return (ns_name_compress(src, dst, (size_t)dstsiz,
106 (const u_char **)dnptrs,
107 (const u_char **)lastdnptr));
108}
109libresolv_hidden_def (dn_comp)
110
111/*
112 * Skip over a compressed domain name. Return the size or -1.
113 */
114int
115dn_skipname(const u_char *ptr, const u_char *eom) {
116 const u_char *saveptr = ptr;
117
118 if (ns_name_skip(&ptr, eom) == -1)
119 return (-1);
120 return (ptr - saveptr);
121}
122libresolv_hidden_def (dn_skipname)
123
124/*
125 * Verify that a domain name uses an acceptable character set.
126 */
127
128/*
129 * Note the conspicuous absence of ctype macros in these definitions. On
130 * non-ASCII hosts, we can't depend on string literals or ctype macros to
131 * tell us anything about network-format data. The rest of the BIND system
132 * is not careful about this, but for some reason, we're doing it right here.
133 */
134#define PERIOD 0x2e
135#define hyphenchar(c) ((c) == 0x2d)
136#define underscorechar(c) ((c) == 0x5f)
137#define bslashchar(c) ((c) == 0x5c)
138#define periodchar(c) ((c) == PERIOD)
139#define asterchar(c) ((c) == 0x2a)
140#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
141 || ((c) >= 0x61 && (c) <= 0x7a))
142#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
143
144#define borderchar(c) (alphachar(c) || digitchar(c))
145#define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c))
146#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
147
148int
149res_hnok(const char *dn) {
150 int pch = PERIOD, ch = *dn++;
151
152 while (ch != '\0') {
153 int nch = *dn++;
154
155 if (periodchar(ch)) {
156 (void)NULL;
157 } else if (periodchar(pch)) {
158 if (!borderchar(ch))
159 return (0);
160 } else if (periodchar(nch) || nch == '\0') {
161 if (!borderchar(ch))
162 return (0);
163 } else {
164 if (!middlechar(ch))
165 return (0);
166 }
167 pch = ch, ch = nch;
168 }
169 return (1);
170}
171libresolv_hidden_def (res_hnok)
172
173/*
174 * hostname-like (A, MX, WKS) owners can have "*" as their first label
175 * but must otherwise be as a host name.
176 */
177int
178res_ownok(const char *dn) {
179 if (asterchar(dn[0])) {
180 if (periodchar(dn[1]))
181 return (res_hnok(dn+2));
182 if (dn[1] == '\0')
183 return (1);
184 }
185 return (res_hnok(dn));
186}
187
188/*
189 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
190 * label, but the rest of the name has to look like a host name.
191 */
192int
193res_mailok(const char *dn) {
194 int ch, escaped = 0;
195
196 /* "." is a valid missing representation */
197 if (*dn == '\0')
198 return (1);
199
200 /* otherwise <label>.<hostname> */
201 while ((ch = *dn++) != '\0') {
202 if (!domainchar(ch))
203 return (0);
204 if (!escaped && periodchar(ch))
205 break;
206 if (escaped)
207 escaped = 0;
208 else if (bslashchar(ch))
209 escaped = 1;
210 }
211 if (periodchar(ch))
212 return (res_hnok(dn));
213 return (0);
214}
215
216/*
217 * This function is quite liberal, since RFC 1034's character sets are only
218 * recommendations.
219 */
220int
221res_dnok(const char *dn) {
222 int ch;
223
224 while ((ch = *dn++) != '\0')
225 if (!domainchar(ch))
226 return (0);
227 return (1);
228}
229libresolv_hidden_def (res_dnok)
230
231/*
232 * This module must export the following externally-visible symbols:
233 * ___putlong
234 * ___putshort
235 * __getlong
236 * __getshort
237 * Note that one _ comes from C and the others come from us.
238 */
239void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
240libresolv_hidden_def (__putlong)
241void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
242libresolv_hidden_def (__putshort)
243u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
244u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
245
246
247#include <shlib-compat.h>
248
249#if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
250# undef dn_expand
251weak_alias (__dn_expand, dn_expand);
252#endif
253